Watch-crystal.



Attest:

New

L. E. F. WACHTER. WATCH CRYSTAL. APPLICATION FILED DEC. :4. I915.

PatentedSept.- 24, 1918 ./7 U mllmm E -0 Inventor: 3 EFfiQCfl/qn {q A tty,

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WATCH-CRYSTAL.

Specification of .Letters ratent. Patented Sept. 24;, 1918 Applicaticu filed December 14, 1915. Serial No. 66,676.

This invention relates to Watches and particularly to the crystal or transparent face covering. Among the objects are to pr0- duce a crystal, using the term generally, that will form a tight joint with and in the casing of a Watch and a secure connection; also to overcome the variations in manufacture and use of crystals and in their fitting. While I use the term crystal, it may include any material suitable for a transparent face cover or" a watch or like article.

In the accompanying drawing I have shown one form of embodiment of my invention, in which A is the outer face of the crystal B is a groove, G is a sloping or beveled portion between the groove and the main face A, D is a beveled or sloping surface between the groove and the other surface of the crystal and forms a radially extending portion of the edge. When used in the form With this extendin ortion the same can serve a snap-retaining edge-0r a guard, or other purposes, and would accommodate any slight irregularity of size either of the casing or of the crystal.

As such crystals are inserted in their position for use in the direction of their convexity, they are pressed and slightly bent to be snapped into position and in the case of material other than glass, as when the crystal is made of celluloid or like material which is more flexible and also subject to variations, the extending edge D serves more readily to facilitate the insertion and also to guard against their falling out in the case of shrinkage. The projection C on the other side of the groove prevents the crystal from falling inward.

My invention may be embodied in various,

forms from What I have herein specifically shown and described,likewise the crystal may be made of various material and vary-. ing dimensions, size and form, but What 1 claim and desire to secure by Letters Patent 1s 1. A Watch-crystal having a circumferential retaining-groove formed in the center of its edge.

2. A Watch-crystal having a circumferential groove formed in the center of its edge.

Signed at New York, this 10th day of De ccmber, 191.5.

LOUIS E. F. WACHTER.

\Vitnesses:

HERMANN F. CUN'rz, H. MUGHMORE. 

